The present invention relates to a shoulder exercise device and method of use. The human shoulder is one of the most anatomically complex joints of the human body, and is capable of some of the most complex patterns of human motion. In many sports, such as baseball, tennis and golf, just to name a few, the shoulder is subject to severe stresses and is susceptible to many types of injury. It is well-established that a regular program of shoulder stretching and strengthening exercises may decrease the incidence of injury. Unfortunately, even though golf, for example, is considered a low-intensity activity, it is not an injury-free activity. More unfortunately, the golf swing is a unique type of motion that is not easily replicated in a training modality. Most golf-related injuries are associated with overuse or poor swing mechanics, and it has been reported that between 8% to 21% of total reported golf injuries occur at the shoulder. To develop effective training and rehabilitative techniques for any athlete, there must be a clear understanding of the mechanics involved in accomplishing the sport.
With more individuals golfing, particularly in the senior sector, injuries are bound to occur. The shoulder joint ranks among the top 5 most injured sites. Problems at the shoulder due to aging include loss of flexibility, rotator cuff degeneration, and acromioclavicular joint degenerative arthritis; all of which can be aggravated by the repetitive nature of the golf swing.
The literature abounds with the importance of sport-specific warm-up, training, and rehabilitation programs. More unfortunately, the golf swing is a unique type of motion that is not easily replicated in a training modality. A review of the literature reveals that shoulder range of motion (ROM) and flexibility is strongly correlated to the age of the subject. Studies discussing shoulder injuries in golf also frequently mention the effects of aging, including the relationship between degenerative changes and rotator cuff tears. Data has revealed that Senior PGA Tour professionals had less upper body rotation at peak backswing than younger PGA Tour professionals. This leads us to ask not only what the normal motions at the shoulder throughout the golf swing are, but also if those motions change with aging and its associated reductions in flexibility and ROM.
Thus, it can be inferred that increasing shoulder ROM and strength, while maintaining the mechanics of a sound golf swing, would be highly helpful to golfers of many skill levels. Perhaps because of the complexity of shoulder motions, various descriptors have been used to describe shoulder motions. For the purposes of this specification, the following terms are defined and used:
Vertical Elevation (VE)
As seen in FIG. 1, an absolute angle between the humerus and a vector connecting a point midway on a line between the shoulder joint centers (S) to a point midway on a line between the femoral joint centers (F) (trunk vector=T). Clinically, this is a combination of shoulder forward flexion and shoulder abduction. An angle of 0° is defined when the upper arm is parallel to the trunk vector and next to the body. In the golf context, the usual motion of gripping a golf club with both hands in preparation for a swing involves placing the hands in close proximity to one another with a slight degree of vertical elevation of the shoulders. Vertical elevation is pictorially seen in FIG. 1, with 0 degrees of vertical elevation representing the arm in a substantially fully dependent position, 90 degree of vertical elevation representing the arm substantially parallel to the shoulder, and 180 degree of vertical elevation representing the arm substantially fully raised above the head.
Horizontal Adduction (HA)
As seen in FIG. 2, motion of the humerus as represented by the motion of an axial line along the length of the humerus (H) in the plane perpendicular to the trunk vector (T) described above (transverse plane of the body). An angle of 0° is defined when the upper arm lies in the plane defined by the trunk vector and the vector connecting the shoulder joint centers (S). For convenience in labeling anterior and posterior motion, an angle of 90 degrees would represent the arm at substantially a right angle to the vector connecting the shoulder joint centers, denominated either +90 degrees for horizontal adduction to the front and −90 degrees for horizontal adduction to the rear. As a function of variable human flexibility, most individuals can horizontally adduct the arm in a forward direction to greater that +90 degrees and even cross the midline, while most individuals cannot horizontally adduct the arm rearward to the full −90 degree range. For the purpose of this specification, the term horizontal adduction is used to denote movement away from the midline, and the term horizontal abduction is used to denote movement towards or crossing the midline of the torso.